Maybe not that weird, but definitely interesting. Biologists from the Erasmus University in Rotterdam and others have constructed a genetic map of Europe. They investigated genotype data from 2,514 individuals belonging to 23 different subpopulations, widely spread over Europe. Although they found only a low level of genetic differentiation between subpopulations, the existing differences were characterized by a strong continent-wide correlation between geographic and genetic distance. This resulted in the following genetic map of Europe (click to enlarge).

The IHT explains: the genetic map of Europe bears a clear structural similarity to the geographic map. The major genetic differences are between populations of the north and south (the vertical axis of the map shows north-south differences, the horizontal axis those of east-west). The area assigned to each population reflects the amount of genetic variation in it.

The map also identifies the existence of two genetic barriers within Europe. One is between the Finns (light blue, upper right) and other Europeans. It arose because the Finnish population was at one time very small and then expanded, bearing the atypical genetics of its few founders. The other is between Italians (yellow, bottom center) and the rest. This may reflect the role of the Alps in impeding free flow of people between Italy and the rest of Europe.

But the study provides more than just an interesting picture. The authors explain that understanding the genetic structure of the European population is important, not only from a historical perspective, but also for the appropriate design and interpretation of genetic epidemiological studies.

This study attempted to determine whether people who live with each other for a long period of time grow physically similar in their facial features. Photographs of couples when they were first married and 25 years later were judged for physical similarity and for the likelihood that they were married. The results showed that there is indeed an increase in apparent similarity after 25 years of cohabitation. Moreover, increase in resemblance was associated with greater reported marital happiness. Among the explanations of this phenomenon that were examined, one based on a theory of emotional efference emerged as promising. This theory proposes that emotional processes produce vascular changes that are, in part, regulated by facial musculature. The facial muscles are said to act as ligatures on veins and arteries, and they thereby are able to divert blood from, or direct blood to, the brain. An implication of the vascular theory of emotional efference is that habitual use of facial musculature may permanently affect the physical features of the face. The implication holds further that two people who live with each other for a longer period of time, by virtue of repeated empathic mimicry, would grow physically similar in their facial features. Kin resemblance, therefore, may not be simply a matter of common genes but also a matter of prolonged social contact.

Weird Science is a new item on Beerkens’ Blog. It presents a peculiar, remarkable, eccentric, extraordinary, unconventional, atypical, strange, funny, odd or bizarre study. In other words: a case of Weird Science.

The Editorial Board of Beerkens’ Blog decided it’s time for a new regular item. Under this new item, I’ll now and then report on a peculiar, remarkable, eccentric, extraordinary, unconventional, atypical, strange, funny, odd or bizarre study. In other words: a case of Weird Science. Here’s the first one.

Several passenger boarding schemes are used by the airline industry in effort to quickly load passengers and their luggage onto the airplane. Since the passenger boarding time often takes longer than refueling and restocking the airplane its reduction could constitute a significant savings to a particular carrier, especially for airplanes which make several trips in a day.

Conventional wisdom would suggest that boarding from the front to the back is the worst case but that boarding from the back to the front is optimal or nearly so. Indeed, this is the strategy that is often employed, boarding passengers in blocks from the rear of the plane to the front. In this case, conventional wisdom only provides an answer that is half right. The worst boarding method is, indeed, to board the plane from front to back. As this study shows, however, boarding the airplane from the back to the front is very likely the second worst method.

The Findings

By boarding passengers in a manner that allows several passengers to load their luggage simultaneously the boarding time can be dramatically reduced. This result contradicts conventional wisdom and practice that loads passengers from the back of the airplane to the front. Indeed, it shows that loading from the back to the front is little different from the worst case of loading from the front to the back. The goal of an optimized boarding strategy should focus on spreading the passengers throughout the length of the airplane instead of concentrating them in a particular portion of the cabin.

By boarding in groups where passengers whose seats are separated by a particular number of rows, by boarding from the windows to the aisle, or by allowing passengers to board in random order one can reduce the time to board by better than half of the worst case and by a significant amount over conventional back-to-front blocks—which, while better than the worst case performed worse than all other block loading schemes. The primary drawbacks for any of these methods is likely to be psychological instead of practical. Groups of passengers who wish to board together would be an issue to investigate from both a customer satisfaction point of view and as a component in a more detailed model.

If a workable method to have passengers line up in an assigned order could be found—and it likely may be employed already, then there is the potential for a substantial savings in time. Such a savings would most likely benefit flights between nearby cities where a particular airplane would make several trips in a given day since it might allow one or two additional flights. Or, it might allow an airline to reduce the number of gates that it requires to meet its obligations since each gate would be cleared more rapidly.